.\"
.\" Copyright (c) 2007 M. Warner Losh <imp@FreeBSD.org>
.\"
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.Dd June 10, 2021
.Dt MMC 4
.Os
.Sh NAME
.Nm mmc
.Nd MultiMediaCard and SD Card bus driver
.Sh SYNOPSIS
.Cd device mmc
.Sh DESCRIPTION
The
.Nm
driver implements the MMC and SD Card bus.
The
.Nm
driver supports all MMC and SD bridges in the system.
All SD or MMC cards in the system attach to an instance of
.Nm .
The
.Nm
bus typically has only one slot, and only memory cards.
MultiMediaCards exist only in memory.
SD Cards exist as memory, I/O, or combination cards.
.Sh SEE ALSO
.Xr mmcsd 4 ,
.Xr sdhci 4
.Rs
.%T "SD Specifications, Part 1, Physical Layer, Simplified Specification"
.Re
.Rs
.%T "The MultiMediaCard System Specification"
.Re
.Sh BUGS
SDIO cards currently do not work.
